1. Field of the Invention
This invention relates to reusing building industrial waste and, in particular, to a carbon dioxide absorber in the form of fine powder of mortar, which is made by crushing fragments of concrete, and to a method for manufacturing the carbon dioxide absorber from concrete fragments released as building industrial waste.
2. Description of the Prior Art
Heretofore, concrete fragments, which are most part of building industrial waste, have been crushed into lumps in the order of 50 mm and are used as a roadbed material or a backfilling material. These ways of use, however, consume only a limited amount of waste, and unused waste, which is inevitably disposed as useless matter, causes a serious problem in terms of industrial waste disposal.
Concrete fragments include aggregate, such as ballast, crushed stone, and so on, and unreacted cement. The existing ways of reusing such waste have been directed only to the use as a roadbed material or a backfilling material, without paying attention to resources contained in concrete fragments, and no consideration has been taken on effective use of the resources.
Under these circumstances, the present Applicant filed a patent application for an invention entitled "Method for Reproducing Aggregate from Building Industrial Waste" in the Japanese Patent Office on Dec. 25, 1991, which proposes to obtain high-quality reproduced aggregate from building industrial waste.
The prior proposal certainly makes it possible to reproduce high-quality aggregate from concrete fragments released as building industrial waste. However, as to processing of mortar released as by-products in the form of fine grains, the prior application merely proposes to use it as a soil modifier by mixing it with reproduced minute aggregate obtained simultaneously and by using unreacted cement component.
It is noted that, along with industrial development and an increase in energy consumption, a progressively large amount of oxygen has been consumed and that carbon dioxide generated thereby continues to break the balance in the global environment and causes global warming.
Although generation of carbon dioxide has been treated as a serious issue, there are still only a few proposals on positive consumption or absorption of carbon dioxide, and the present status is far from solution of the issue.